Outlet for electrical conduits and method of applying the same



H. J. RQBERTSQN, JR 1,946,237 OUTLET FOR ELECTRICAL CONDUITS AND METHOD OF APPLYING THE SAME Filed April 17, 1931 INVENTOR ni- HUGH J. RoBERTsoNJR ATTORNEYS` 30 of spacing. Some buildings may require on one Patented Feb. 6, 1934 UNITED( STATESy PATENT OFFICE OUTLET FOR ELECTRI CAL CONDUITS ANDV METHOD F APPLYING THE SAME Hltlh J. Robertson,

1 Claim.

the oor at a desired point over a duct buried therein, making an opening then in the top of the duct, applying an voutlet in the opening in such way as to support it on the duct, repairing the ooraround the wires in the duct, through the outlets, buried in the oor material and extending through it to the Iioor surface.

eighteen inches thereon. The saddle-shaped outlet comprises an open supporting base concaved to snugly t and rest upon the outer curved surface o1' the conneck projecting from side walls of the duct. The position of the out- 56 let is not controlled by prearranged openings Jr., New York, N. The Fibre Conduit Company, Orangeburg,

., a. corporation of New York Application April 17, 1931. Serial No.

through the duct, so that variable `be used for it. As the duct remains intact, ac-

the the\oor.

been opened, plying an electric tting thereto.

means for attaching a oor riser.

ing the outlet consists in a saddle-shaped clamp or clasp, prei'- Y., assis-nor being uninterpassages or outlet fittings, presents a the ends oi.' the shing Wires.

an already finished floor strucby excavation and refinishing of the latter,

1t 1s primarily intended that a number of In the accompanying drawing- Figure v1 shows in cross-section one form of applied.

Figure 3 is a plan view. Figure 4 is a partial sectional view of a modified construction, and

Figure 5, a side view thereof. I have illustrated in the The preferred means for to the attachduet after the latter is laid I netal,

have outturned edges or anges 5 to anchor it in the cement floor when the latter is laid. This ferm also facilitates the slipping of the saddleshaped clamp over the duct.

An alternative form for use for example with bottom 2 and having their lower edges in direct contact with the floor mathat the below the edges of the duct, is illustrated in Figure 4. in which the thin plate 3b of yielding but non-resilient metal has the tongue 3c at its lower edge, provided with a sharp projection 3d which may be driven into the duct when the tongue 3c is forced into contact with the latter. Only a portion of the outlet is shown in Figures 4 and 5. The remainder will conform to the shape of the duct and straddle it like the form shown in 1 and have the same construction on the part above the duct.

'I'he width of the saddle-shaped clamp lengthwise of the conduit is such as to prevent the tilting of the outlet assembly by longitudinal strains, and hold it firmly while the cement of the floor is being poured. At the top of the member 3. an aperture 3a of suitable diameter is provided, around the margin of which is formed or attached an interiorly screw-threaded outlet neck or nipple 6 not supported by being attached to the duct by engagement within an aperture made in the duct top, as in the construction now usual, it being here supported by the yoke arms 3 entirely outside the duct and it can therefore be applied without opening the top of the duct. Within it may be screwed the threaded ring 'I which is adjustable to the height desired, and to which may be applied the electric fixture or floor riser. I have here shown a flanged nut 11, the ange of which is of the thickness of the floor covering 12, an adjustable bushing 13, and part of a iloor riser tube or pipe 14. Any other form of fixture and method of applying it to the outlet assembly may be employed. For example, the pipe 14 may be of larger diameter and be screwed directly into the nut 11. The construction of the outlet assembly clamp, as here illustrated, has a laterally extended boss 15 to afford a plane surface tangential to the curve of the clamp, through which the aperture 3a is made, and to stiften the resilient action of the clamp, and increase the resistance of the clamp to the load to be sustained by the nipple.

In one way of laying a floor in which this invention is to be used, the bottom course of the floor is, as illustrated at 8, first laid. The duct 1 is then laid directly thereon as shown. Any other preferred way of providing support for the duct, may be employed. Th'e saddle-shaped clamps, comprising the neck 6 and the yoke arms 3 extending laterally therefrom, are then applied thereto at optional intervals along its length, by forcing them down over the duct from the top so that they will be securely held thereon as by the resilient action of the yoke arms, or by forcing in the pointed projections 3d. The rings 'l may be thereupon applied to the individual saddleshaped clamps, or they may be in place when the clamps are applied to the duct. The duct is preferably left imperforate until any particular outlet is to be used for attaching a floor riser as shown in Figure 1. The ring 'I is adjusted to a height which will bring its top edge flush with the door surface. The upper portion 8a of the cement flooring i3 then poured, whereupon the duct is completely buried beneath the floor, as well as the outlet assembly and the ring 'l up to or near the floor surface. A cap 9 is placed in the top of the ring 'I while the floor is being poured to prevent access of cement to the interior of the ring. Should for any reason the cap 9 have been displaced or not used and any cement get within the ring while the floor is being laid, or the outlet itself dislodged, cement will not enter the duct and can be readily chipped out or removed when the outlet is to be used. Also no water can leak into the duct and impair the insulation of the wires therein. When the outlet is to be used, a hole is made as usual through the iioor covering l2, if any, the cap 9 is removed, and a hole made through the conduit, as shown in Figure 2, immediately below the ring '1. A ferrule 10, preferably of insulating material, having its central passage flared at both ends, is then fastened in place, preferably by screwing it down ln the ring '7 until the shoulder 10a on the ferrule comes into supporting contact with the wp of the duct. 'I'he rounding of the ends of the passage through the ferrule facilitates the making of proper electrical connections from the wires within the duct to the floor riser or other nxture. without abrasion of the insulation.

The structure of my invention has two important advantages: the placing of the outlet is made optional and selective, and the opening of the duct may be delayed until the use of any out- The structure here described involves a duct buried in the floor material, in connection with which outlet assemblies are used which are applied before the floor material is poured-but in which the duct, at the outlet, preferably remains imperforate until access is tc be had at that point.

I claims- In `an underfloor duct system, the combination with a conduit having an imperforate wall presenting a curved outer surface, of a` pre-set conduit outlet comprising a concave base shaped to snugly fit and rest upon said curved surface and having a wire outlet opening, a tubular neck or collar supported by and proiecting from said base in registry with said outlet opening, and fastening means carried by said outlet base engaging said conduit, whereby an outlet port can be cut through the wall of said conduit in registry withthe opening through said outlet when the same is to be used.

HUGH J. ROBERTSON, Jl. 

